1. Field of the Invention
The present invention relates to a bellows type air spring and a vehicle height adjustable suspension using the same.
2. Discussion of the Background
FIG. 11 illustrates an example of conventional suspensions, which includes an upper mount unit 60 mounted on a chassis 50, a shock absorber 70 mounted to the upper mount unit 60, upper and lower dish-like receiving plates 80a and 80b, and a coil spring 90 which is mounted between the upper and lower retainer members in a compressed state.
The upper mount unit 60 includes a rod holder 65, which in turn includes an annular member 61 made of metal and an annular damper rubber 62 provided around the annular member 61, an annular mounting plate 66 fixed around an upper portion of the circumferential periphery of the rod holder 65, and a dish-like receiving plate 67 fixed around an lower portion of the circumferential periphery of the rod holder 65.
The mounting plate 66 is provided with a plurality of stud bolts, which respectively extend through holes (not shown) formed in the chassis 50, and are threadedly engaged with nuts (not shown), thereby mounting the upper mount unit 60 on the chassis 50.
The shock absorber 70 includes a body 71 formed from a hydraulic cylinder, and a retractable rod 72 retractably mounted in the body 71. The retractable rod 72 forms at its outside end an outwardly threaded portion 73, which passes the upper dish-like receiving plate 80a, and is received in the annular member 61 of the rod holder 65 of the upper mount unit 60 via a washer 81. The outwardly threaded portion 73 protrudes upwardly and is threadedly engaged with a nut 82, thereby mounting the shock absorber on the upper mount unit 60.
On the other hand, the upper dish-like receiving plate 80a urged upwardly by the coil spring 90 is pressed against the dish-like receiving plate 67 of the upper mount unit 60 via a bearing 83.
When the coil spring 90 is to be replaced with a new one, the coil spring 90 in the shock absorber 70 is compressed to a predetermined length by using a spring compressor (not shown) as a safety device, and then the lower dish-like receiving plate 80b is cut while retaining the coil spring 90 in a compressed state. The coil spring 90 is then removed from the shock absorber 70, and a new one is mounted in position.
Next, the new coil spring 90 is compressed in the same manner as the above, and the lower dish-like receiving plate 80b is welded on the body 71. The coil spring 90 is gradually elongated to such a length as to abut against the lower dish-like receiving plate 80b by the spring compressor. After that, the spring compressor is removed.
The above conventional suspension requires the compression of the coil spring 90 by the spring compressor, cutting of the lower dish-like receiving plate 80b and other works for the replacement of the coil spring 90 and hence adjustment of the vehicle height. These works are troublesome and time consuming.
It is an object of the present invention to provide a bellows type air spring that allows a currently mounted suspension to adjust the height of a vehicle in simple, secured and prompt manners without the necessity of modification of the basic structure of the vehicle, while effectively using an upper mount unit, a shock absorber, etc., of the currently mounted suspension.
It is another object of the present invention to provide a vehicle height adjustable suspension using the bellows type air spring.
In consideration of the above problems, there is provided a bellows type air spring, which includes a bellows body, and first and second end members. The bellows body has a generally hollowed cylindrical shape with upper and lower open ends and a longitudinal axis extending between the upper and lower open ends. The bellows body also defines therein an air chamber for receiving the air, thereby allowing the bellows body to be expanded and contracted along the longitudinal axis. The first end member is disposed in the lower open end for sealing the same, and defines therein a through hole for receiving a body of a shock absorber. The second end member is disposed in the upper open end for sealing the same, and defines therein a through hole for receiving a retractable rod of the shock absorber.
Accordingly, when the currently used suspension includes the combination of the coil spring and the shock absorber, the bellows type air spring having the above arrangement allows the currently mounted suspension to adjust the height of a vehicle in simple, secured and prompt manners without the necessity of modification of the basic structure of the vehicle, while effectively using the upper mount unit, the shock absorber, etc., of the currently mounted suspension.
The bellows type air spring is expanded and contracted along the longitudinal axis thereof by the air introduced, thereby adjusting the height of the vehicle in flexible and simple manners.
The safety device used in the conventional coil spring is not needed any more to replace the bellows type air spring with a different one, resulting in shortening of the replacement time of the spring, and a simpler operation.
An air valve mounting portion is preferably provided in at least one of the first end member and the second end member. This air valve mounting portion is adapted to be connected to an air feeding passage to introduce the air into the bellows body and discharge the air from the bellows body via the air valve mounting portion. With this arrangement, the air introducing and discharging portion can be varied in position according to the body structure (e.g., frame structure, monocoque structure, etc.) of the vehicle currently used.
According to another scope of the present invention, there is provided a vehicle height adjustable suspension including a bellows body, a first end member, a second end member, a shock absorber, a spring receiving member, and an adapter. The bellows body has a generally hollowed cylindrical shape with upper and lower open ends and a longitudinal axis extending between the upper and lower open ends. The bellows body also defines therein an air chamber for receiving the air, thereby allowing the bellows body to be expanded and contracted along the longitudinal axis. The first end member is disposed in the lower open end for sealing the same, and defines therein a through hole. The second end member is disposed in the upper open end for sealing the same, and defines therein a through hole. The shock absorber includes a body extending through the through hole of the first end member, and a retractable rod extending through the through hole of the second end member. The spring receiving member is secured to the body of the shock absorber and hermetically mounted on the first end member, thereby allowing the bellows body to be securely received by the spring receiving member. The adapter is hermetically mounted on the second end member.
According to the above arrangement, it is possible to replace the currently used suspension with the vehicle height adjustable suspension of the present invention by the replacement of the currently used suspension itself without the necessity of modification of the basic structure of the vehicle. Hence, a simple, secured and prompt operation is obtainable.
As an additional advantage of the vehicle height adjustable suspension, it is applicable to the vehicle without the upper mount unit.